Restless Legs Syndrome Foundation Blog

January 28, 2026

Commonly Used Rating Scales in RLS Research

Research related to RLS often relies on questionnaires and rating scales to provide objective clinical data. These tools provide a baseline to help researchers and clinicians assess clinical diagnoses and evaluate symptom severity, treatment effectiveness and patients' physical and emotional well-being. Understanding these scales can make it easier to interpret published research findings and clinical results.

International RLS Study Group Score (IRLS)

The International Restless Legs Study Group (IRLSSG) developed and validated a 10-item rating scale to indicate how symptoms have affected a patient over the course of one week. This test is administered by a physician, but answers are self-reported by the patient. Each of the 10 questions asks the respondent to rate their experiences with RLS on a scale from 0 (no symptoms) to 4 (severe and frequent symptoms), producing a total score between 0 and 40. Generally, scores in the range of 1–10 correspond to mild RLS, 11–20 to moderate, 21–30 to severe, and 31–40 to very severe RLS.

How is it used? The IRLS is a commonly administered questionnaire used in research and clinical practice to rate the severity of RLS symptoms and can be used to help determine the best course of treatment for RLS patients.

RLS-6 Scale

The RLS-6 scale measures the impact of RLS on daily life. This 6-item questionnaire evaluates questions on a scale from 0 to 10, with higher numbers indicating more severe RLS. The questions ask for individuals to rate satisfaction with sleep and severity of symptoms while falling asleep, during the night, during the day while sitting or lying, and during the day when moving around.

How is it used? The RLS-6 is an instrument to assess RLS severity within specific and pragmatic parameters. It can be used to supplement the IRLS.

Cambridge-Hopkins Diagnostic Questionnaire (CH-RLSq)

This questionnaire is a validated diagnostic tool used by physicians to assess and identify RLS. The questions address basic diagnostic features of RLS such as frequency and timing of symptoms, relief of symptoms with movement, and impact on daily life or sleep patterns.

How is it used? The CH-RLSq is commonly used in research to validate RLS diagnoses and differentiate RLS from conditions with similar characteristics.

Suggested Immobilization Test (SIT)

The SIT is a validated tool that assesses leg discomfort and leg movements during a 60-minute period. The test is administered in the evening in a clinical setting. Participants recline at a 45-degree angle with legs outstretched and are instructed to avoid voluntary movement for the duration of the test. The test records surface electromyograms from the anterior tibialis muscles to detect leg movements. A high number of leg movements during the test may help differentiate patients with RLS from those without RLS.

How is it used? The SIT provides a standardized testing condition to measure the severity of RLS symptoms by quantifying leg movements and subjective discomfort. This test is often used to determine whether potential treatments might be helpful to treat RLS symptoms.

Pittsburgh Sleep Quality Index (PSQI)

This validated questionnaire is administered by a physician and evaluates overall sleep quality over a one-month period. The questions fall into seven categories: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Five additional questions rated by the respondent’s roommate or bed partner are included for clinical purposes but are not scored. Each question is scored from 0 to 3, with higher scores indicating greater sleep disturbances.

How is it used? The PSQI may be helpful during RLS research studies to determine the effectiveness of medications, interventions and other therapies for improving sleep.

The World Health Organization-5 Well-Being Index (WHO-5)

This questionnaire evaluates five statements to measure mental well-being over two weeks. Statements are rated on a 6-point scale, with higher scores indicating better mental health.

How is it used? The WHO-5 may be used in RLS research to study the relationship of RLS and mental health or to examine mental health outcomes based on treatment response.

RLS Foundation and American Academy of Sleep Medicine Foundation Announce 2025 Research Grant Awardees

August 4, 2025

November 3, 2024

RLS Foundation 2024 Research Grant Program Awardees

Each December, the RLS Foundation announces the opening of preapplications for research grant proposals through its Research Grant Program. Since its inception in 1997, this program has focused on supporting efforts to develop better treatments for RLS and ultimately find a cure. Researchers can apply for grant proposals of a 1 year-duration, with funding levels of up to $50,000.

This year marks a significant milestone: for the first time, the RLS Foundation is funding four RLS research studies in the same year! This historic level of support is made possible by our dedicated members and a collaboration with the American Academy of Sleep Medicine Foundation (AASMF), which co-funded one of the grant awards. Each project aims to deepen our understanding of the genetic, biochemical, and cellular mechanisms of RLS.

We are excited to introduce the innovative researchers leading these groundbreaking studies:

Shawn Hochman, PhD

Emory University School of Medicine, Atlanta, Georgia

RLS Foundation and AASMF Co-Funded Grant

Grant Title: Sensory dysfunction in a diet-induced iron-de¬ficiency mouse model of RLS: Characterization and control by dopamine-sensitive spinal gating circuitry

Objective: This study aims to use electrophysiological and genetic approaches in mice to study whether an iron-deficient diet leads to; (1) increased excitability in select ‘pain-like’ pe-ripheral sensory signals arising in calf muscles, (2) whose activa¬tion of central circuits is abnormally amplified due to deficient capacity for dopamine-sensitive inhibitory gating signals in the spinal cord. As an individual with RLS, I fully appreciate the suf¬fering associated with abnormal limb sensations and the imme¬diate relief provided by leg movements.

Imad Ghorayeb, MD, PhD

Hospital Center University De Bordeaux, France

Grant Title: Functional connectivity of the interoceptive network in RLS: An anatomo-clinical prospective study

Objective: This project will precisely characterize the intero¬ception awareness in RLS patients together with the time vari¬ance of the symptoms and their sleep/wake cycle impairment using ambulatory assessment. This assessment of the symp¬toms will be correlated to time-of-day intrinsic connectivity of the insula, based on both static and dynamic connectivity frameworks. Such a survey may confirm the hypothesis that interoceptive dysfunction in patients with RLS would link the sensorimotor and non-motor symptoms of the disorder into a common pathophysiological process.

Brian Koo, MD

Yale Center for Sleep Medicine, New Haven, Connecticut

Grant Title: Cerebrospinal Fluid Melanocortin and Endor¬phin in Restless Legs Syndrome Related Augmentation

Objective: This proposal aims to study melanocortin biology among RLS patients suffering dopamine agonist-induced augmentation and in the post-augmentation stabilized state, having been taken off the dopamine drug and treated with a non-dopamine medication. This proposal focuses on the neurobiological interaction between dopamine and MC biol¬ogy, first assessing cerebrospinal fluid MCs (α-MSH, β-MSH, β-EDP) in the chronic dopamine agonist setting, and then in the post-dopamine agonist setting.

Mauro Manconi, MD, PhD

Sleep and Epilepsy Center, Civic Hospital Neurocenter of Southern Switzerland

Grant Title: Epidural Spinal Cord Stimulation in Refractory or Augmented Restless Legs Syndrome

Objective: This research consists of a pilot interventional study with the general aim to test the efficacy and safety of epidural spinal cord stimulation (SCS) in patients with moderate to very severe RLS that is refractory, or intolerant to standard treatments. This is a proof-of-concept, open-label clinical trial.

Congratulations to the 2024 grant awardees! An in-depth review of each study will be published in the Fall edition of the RLS Foundation's quarterly magazine, NightWalkers. If you are not yet a member of the RLS Foundation and would like to receive a subscription to NightWalkers, visit our website at www.rls.org.

September 17, 2024

RLS Foundation Partners with The American Academy of Sleep Medicine Foundation (AASM Foundation) to Fund Research

The American Academy of Sleep Medicine Foundation (AASM Foundation) is pleased to join forces with the Restless Legs Syndrome Foundation (RLS Foundation) to fund research leading to new treatments and a cure for restless legs syndrome (RLS).

Earlier this year, the AASM Foundation began an agreement with the Restless Legs Syndrome Foundation to co-fund basic and clinical RLS research. The partnership for 2024 includes the following research priorities:

• Neurobiological interaction: Elucidate the points of interaction between RLS-relevant neurotransmitters, neuronal pathways, and iron deficiency.
• Pharmacologic treatments: Elucidate effects of novel pharmacological approaches on RLS.
• Clinical Practice: research based on innovations in patient care delivery including but not limited to population health programs, technology-enabled healthcare delivery (i.e. Telemedicine) and public health initiatives.

The recipient selected for this joint award is Shawn Hochman, PhD, from Emory University School of Medicine on the topic: Sensory Dysfunction in a Diet-Induced Deficiency Mouse Model of RLS: Characterization and Control by Dopamine-Sensitive Spinal Gating Circuitry.

We are excited to continue this partnership with a new grant cycle that will open later this year.

About the AASM Foundation:

The AASM Foundation is the official philanthropy of the American Academy of Sleep Medicine. Our values, programs, and purpose are focused on investing in people, research, and communities to improve the sleep health of all people. Learn more about the AASM Foundation by visiting foundation.aasm.org.

March 5, 2021

Stefan Clemens, an East Carolina University (ECU) associate professor at the Brody School of Medicine’s Department of Physiology, was awarded a US patent for his novel method of treating restless legs syndrome (RLS), which could lead to more effective care over a longer period of time for patients.

RLS is frequently treated with dopaminergic drugs to replace or prevent the loss of dopamine. While these drugs can deliver a high initial effect, they often lose their effectiveness over time and symptoms can worsen, a side effect known as augmentation. Classic RLS treatments act on a dopamine receptor known as D3, which has a suppressive effect in the nervous system.

Clemens’ animal models show that over time the medication leads to an increase of a different, excitatory receptor subtype, D1. This increase of the D1 receptor might be the cause of augmentation. Clemens’ patent, which he received in late August 2020, targets the increased D1 receptor levels in RLS patients suffering from augmentation, leading to reduced activation of D1 receptors while providing traditional therapy relief from RLS.

“Our lab postulates that this new compound will maintain long-term efficacy for RLS,” Clemens said. “If augmentation begins, we predict that we can reduce D1 receptor activation in patients and balance things back out, keeping the treatment effective.”

Using a grant from the North Carolina Biotechnology Center, Clemens and a collaborator from the University of Houston will run a small pilot study of the new treatment method. His work also gained the attention of a company that has interest in establishing a partnership where ECU’s patent rights may be used in combination with its existing drug formulation for treating augmentation. “The patent would not have been issued without their help,” said Clemens, who is also working on medical treatments for opioid pain tolerance. “I now know that it can be very beneficial to have experts in other areas come from different angles that make us think of other ways to use our work.” Clemens is a member of the Foundation's Scientific and Medical Advisory Board and is the Chair of the Research Grant committee.